1. Field of the Invention
The present invention relates generally to motorcycle clutches. More particularly, the present invention relates to clutches for off-road racing motorcycle applications.
2. Description of the Related Art
Off-road racing motorcycles intended for older, and often more experienced, riders often utilize a manually controlled clutch and a multiple speed transmission, offering up to five or six different gear ratios. Conversely, most off-road motorcycles for riders of four to nine years in age utilize an automatically engaging clutch and single-speed transmission.
Eliminating the need to shift gears and control the engagement of the clutch reduces learning time for younger, or inexperienced, riders. An automatically engaging clutch also improves safety by allowing inexperienced riders to fully concentrate on maneuvering the motorcycle. Furthermore, in off-road motorcycle competitions (e.g., motocross races), riders in certain age groups and/or engine displacement categories, are required to ride a single speed motorcycle equipped with an automatically engaging clutch.
However, the clutch is not only used by motorcycle riders and racers when shifting the transmission, but is also used to control the overall speed and power delivery of the motorcycle by interrupting engine torque from reaching the rear wheel. For example, the rider may slow the overall speed of the motorcycle while negotiating a corner by briefly disengaging the clutch, instead of altering the throttle position. This method keeps engine speed high in order to have substantial engine torque available immediately upon subsequent re-engagement of the clutch. Experienced off-road motorcycle riders also use a manual clutch to produce a “burst” of acceleration, irrespective of shifting the transmission.
A rider of a motorcycle having an automatically engaging clutch must reduce the position of the throttle to slow the speed of the motorcycle in order to negotiate a corner. Upon exiting the corner, as the rider increases the throttle position, there is a delay in engine torque reaching the rear wheel of the motorcycle due to the time that is necessary for the automatic clutch to re-engage. While this condition may be tolerable for recreational or novice riders, it presents a disadvantage to experienced riders, and racers, of motorcycles having an automatic clutch.
Therefore, a need exists for an improved automatically engaging clutch that may be disengaged without having a delay in torque transfer upon subsequent re-engagement.